Reflector for radiant heaters



Feb. 21,'192s.. 1,659,897

J. SCHOENFELD REFLECTOR FOR RADIANT HEATERS Filed April 6. 1925 M57741. REFLECTOR emu/v0 COA T GL'ACE' 60.4 T

GOLD IN V EN TOR.

Faten'led Feb. 21, 192%.

I unites stares ear I J'QSEPE SCEOENEELD, OF ALAMEDA, CALH ORNIA, ASSIGNOR TC THE MAGNAVOX COM- "ear est tes.

PARTY, OF SAN FRAHCISCQ, CALIFURNIA, A CORPORATION OF ARIZONA.

REFLECTQE FOE.- RQDEMTE HEATERS.

.hpplicatior. filed April 19535. {Serial Iio. $9,879.

This invention relates to reflector heaters, such as electric heaters and the like.

While electric heaters of the reflector type have beeniin more or less general use for a considerable number of years, commercially, they have not been as successful as other types of electric heaters since their general efliciency has been low. Such heaters are fairly efficient when the reflectors are new and bright, but the reflectors being subjected to the high temperature of the heating elements, become oxidized or tarnished and gradually lose their efficiency.

The object of the present invention is to generally improve and simplify the construction, operation and efficiency of re flectors of the character described, and particularly to provide a reflector for electric heaters which will not oxidize or tarnish when subjected to the high temperature of the heating elements or from atmospheric influences.

One form which my invention may assume is exemplified in the following description and illustrated in the accompanying drawings, in Which Fig. l is a transverse vertical section of a radiant type of electric heater.

Fig. 2 is an enlarged cross-section of a portion of the reflector showing the manner in which it is coated to prevent oxidation.

Referring to the drawings in detail, and

particularly to Fig. 1, A indicates in gen eral an electric heater, the heater compr1s-=. ing a stand B upon which is mounted a reflector 2. Mountedwithin the reflector is an electric heat resistance element 3, which is maintained at a fairly high temperature when the heater is in use. The reflecting surface of heaters of this character is, as

previously stated, subjected to the high temperature of the heating element and this.

-majority of the heat andlightrays radiating from the heating element will be reflected and projected in a forward direction. The most eflicient surface of the reflector is that immediately adjacent the heating elements as this portion of the surface receives the greatest amount (if heat and light rays. This surface is also closest to the heating element and it is for this reason that it rapidly heats and oxidizes the metal. As

following manner: The reflector proper may be constructed of any suitable metal;v

for instance, such as soft iron' or steel. This. is stamped or otherwise shaped between dies or the like and it is then annealed, pickled and otherwise cleaned to remove all traces of grease and dirt. The interior surface of the reflector which serves the function of reflecting and projecting the light and heat rays is then enamelled or glazed, this being accomplished by first spraying or otherwise applying a grounding coat thereon which contains silica or the like combined with a suitable fusing material so as to produce a more or less glazed surface when baked in an oven at a temperature of 1600 F. After the grounding coat has been applied, a glazing coat consisting of substantially the following composition is next applied, in approximately the following proportions:

70 barium carbonate, 180 borax, 500 flint, 500 feldspar, 70 soda ash, 70 saltpetre, 150 cryolite, 75 boric acid.

The reflector is again placed in the oven and subjected to a temperature of approximately 1400 to 1600 F. The two coatings of glazing material form a smooth, polished surface which is ideal for the reception of the finalreflecting material or surface'which is last applied. This material consists of a non-oxidizing metal, such as gold, which may be applied in the form of a chloride.

far been obtained by means of a chloride solution of a proximately 10% strength, as a thin uni orm film of gold may in this manner be applied.

A reflector constructed in this manner may be subjected to the high temperature of the electric resistance or heating element With out tarnishing, as gold is not readily oxidized at temperatures less than 1800 F. In actual practice, the temperature assumed seldom exceeds 600 F., due to the rapidity with which the heat is liberated by means of conduction, radiation, convection and otherwise, so the chance of oxidizing the gold film is entirely eliminated. The "temperature of the resistance or heatin element proper seldom exceeds 1200 and it is for this reason that temperatures in excess of 600 F. are not exceeded in the reflector proper.

Gold has been specified as the material most suitable forthepresent purpose. as it v lain is usually glazed during its manufacture.

Having thus described my invention, what "I claim and desire to secure by Letters Patent is 1. As an article of manufacture, a reflector for heaters comprising a body having a ground coat, a glazing coat united with the ground coat and consisting of barium carbonate, borax, flint, feldspar, soda ash, saltpetre, cryolite and boric acid, and a film of gold united with the glaze coat to provide a reflecting surface.

2. As an article of manufacture, a refiec tor for heaters comprising a body having a ground coat, a glaze coat united with the ground coat, and a thin film of gold united with the glaze coat.

3. As an article of manufacture, a reflector for heaters comprising a body havinga ground coat consisting of silica combined with a fusing material, a glaze coat on the ground coat, and a thin film of gold on the glaze coat, the silica supporting the gold.

JOSEPH SCHOENFELD. 

